Refrigeration And Air Conditioning Model Question paper : All the candidates preparing for ITI RAC need very important study material related to this exam so that they can prepare for this exam in the best way. So for the candidates who are preparing for ITI RAC, in this post of ours, some important questions asked in the ITI RAC exam and their answers have been given, which you should read carefully, these questions have already been asked in many ITI RAC exams and can be asked in the upcoming exams.
ITI Turner Theory Model Paper in Hindi
Refrigeration And Air Conditioning Model Question paper
1. Which of the following is not a positive displacement type compressor?
• Rotary vane compressors
• Rotary screw type compressors
• Centrifugal compressors
• Acoustic compressors
Answer: Centrifugal compressor
2. Hermetic compressors are used mainly in small systems because
• They produce high COP
• They have the flexibility to use any refrigerant
• They do not require frequent servicing
• Can be used under various load conditions
Answer. They do not require frequent service
3. In reciprocating compressors, clearances are provided to:
• Improve volumetric efficiency
• Increase life of the compressor
• Fit valves
• Reduce power consumption of the compressor
Answer. To install valves
4. ……….. is filled in the filter dryer to absorb moisture.
• Coal
• Silica gel
• Sand
• Chalk
Answer. Silica gel
5. Which of the following devices is fitted between the condenser and capillary inlet?
• Hot gas muffler
• Oil separator
• Heat exchanger
• Dryer
Answer. Dryer
6. What is the location of accumulator?
• Evaporator inlet
• Condenser inlet
• Evaporator outlet
• Condenser outlet
Answer: Condenser outlet
7. What are the causes of frosting in filter drier?
• Thermostat in cut out position
• High voltage
• Choking
• Low voltage
Answer: Choking
8. The condenser removes ………. from the refrigerant.
• Sensible heat only
• Superheat only
• Latent heat only
• Sensible heat and latent heat
Answer: Sensible heat and latent heat
9. Natural draft cooling tower can be installed in:
• Indoor
• Walled area
• Open area
• Anywhere
Answer. In a place surrounded by walls on all sides
10. Which of the following processes cools water in a cooling tower?
• Condensation
• Evaporation
• Radiation
• Conduction
Answer: Radiation
11. Cooling is produced by…..
• Condensation
• Radiation
• Evaporation
• Absorption
Answer: Radiation
12. If calcium carbonate gets deposited in the pipes,
• It obstructs the flow of water
• Reduces the inner diameter of the pipes
• Impedes heat exchange
• All of the above
Answer: All of the above
13. Cooling water treatment formulations are designed to:
• Minimize scale formation
• Aid in deposit control
• Minimize corrosion
• All of the above
Answer: For all of the above
14. Open recirculation cooling system is corrosive because it is saturated with……..
• Oxygen
• Hydrogen
• Nitrogen
• Carbon dioxide
Answer: Oxygen
15. Which of the following prevents the formation of excessive solid concentration in tower water?
• No blow down
• Intermittent blow down
• Continuous blow down
• Rare blow down
Answer: Intermittent blow down
16. Oxygen concentration in a closed system is ……… compared to an aerated system.
• Less
• More
• Uniform
• Slightly more
Answer: less
17. Fouling of heat transfer surface………..
• Decreases insulating effect
• Has no effect on insulating
• Increases insulating effect
• None of these
Answer: Increases the insulating effect
18. If scale formation is not controlled,
• Will decrease the rate of heat transfer
• Will have no effect on heat transfer
• Will increase the rate of heat transfer
• Will have negligible effect on heat transfer
Answer: It will decrease the rate of heat transfer
19. Capacity of water cooler is expressed in…….
• Tons of refrigeration
• Cubic feet
• KaCI/TR
• Liters
Answer: Litre
20. What is most commonly used as insulating material in water coolers?
• Fibre Glass
• Cork
• PUF
• Glass Wool
Answer: Cork
21. Which type of tap is used in water cooler to prevent wastage of water?
• Hose type
• Push type
• Lever type
• Regulating type
Answer: Lever type
22. Float assembly is used for?
• Bubble top coolers
• Instantaneous
• Stantaneous coolers
• Storage coolers
Answer: Storage cooler
23. What is dry ice?
• Ammonia
• Carbon dioxide
• Carbon monoxide
• H2O
Answer: Carbon monoxide
24. The outer body of water cooler can be cleaned using ……..
• Normal water
• Lukewarm water
• Cold water
• Hot water
Answer: Cold water
25. What is the result of high ambient temperature around a water cooler condenser?
• No cooling
• Adequate cooling
• Undercooling
• Excessive cooling
Answer. There will be suitable cooling
26. A refrigerator ice maker converts water into ice cubes. During this process the entropy of water
• increases
• decreases
• remains unchanged
• is lost
Answer: remains unchanged
27. What is the purpose of a home icemaker heating coil?
• To warm the bottom of the ice mold
• To prevent frost
• To defroster the refrigerator
• None of the above
Answer. Heating the bottom of the ice mold
28. Why do ice cubes look clear?
• Water freezes slowly
• Water freezes in layers
• All water freezes at once
• None of these
Answer: All the water freezes at once
29. Why do ice cubes look cloudy?
• Water freezes slowly
• Water freezes in layers
• All water freezes at once
• None of the above
Answer: Water freezes in layers
30. What is the name of the tube that carries refrigerant to the evaporator?
• Closed circuit
• Open circuit
• Short circuit
• Parallel circuit
Answer: Open circuit
31. Which of the following can cause excessive frost in a freezer?
• Low refrigerant pressure
• High outside temperatures
• Freezer door not sealing properly
• None of the above
Answer. Freezer door not sealing properly
32. What is the ideal distance between freezer coils and wall?
• 3 to 5 inches
• 6 to 8 inches
• 9 to 11 inches
• 12 to 14 inches
Answer: 3 to 5 inches
33. What is meant by the term ‘heat of respiration’?
• Heat leaking from insulation
• Heat load from fresh fruits and vegetables
• Heat load when door is open
• Heat load from condenser
Answer. Heat load from fresh fruits and vegetables
34. What is that object called whose potential difference is between that object and the earth?
• Live
• Earth electrode
• Dead
• Resistance area
Answer. alive
35. Pasteurisation is the process of preserving which of the following?
• Solid food
• Liquid food
• Any food
• None of the foods
Answer: Any food
36. Salting draws out …….. from meat through the process of osmosis.
• Moisture
• Carbon dioxide
• Heat
• Bad odour
Answer: Humidity
37. Fermentation is the process of microbial conversion of starch and sugar into ………
• Mold
• Enzymes
• Bacteria
• Alcohol
Answer: Alcohol
38. Quickly cooling food to a temperature as low as is relatively suitable for keeping it safe from microorganisms is called?
• Accelerated chilling
• Blast chilling
• Jet chilling
• Explosive chilling
Answer: Jet chilling
39. Which of the following is not true about blast freezer?
• Quality of food is maintained
• It slows down metabolic activity
• Bacterial growth is slowed down
• It consumes less energy
Answer: It consumes less energy
40. What is the effect of excessive frost accumulation inside a deep freezer?
• Decreases the temperature of the freezer
• Food material gets spoiled
• Acts as insulation
• Keeps food fresh
Answer: Food gets wasted
41. Which type of condenser is used in water cooler?
• Forced draft
• Water cooled
• Natural draft
• Coolant cooled
Answer: Forced draft
42. Water inlet flow of water cooler is controlled by?
• Solenoid valve
• Expansion valve
• Float valve
• Pressure regulating valve
Answer: Expansion valve
43. Filter drier removes…….
• Oil
• Moisture
• Acids
• Sludges
Answer: Acid
44. Which type of cooling coils are generally used in deep freezers?
• Flooded type
• Forced draft
• Natural draft
• Finned coil type
Answer: Forced draft
45. Ball bearings of electric motors are lubricated by …….
• Oil
• Grease
• Air
• Water
Answer: Air
46. Bimetallic strips are made of two different metals each having different rate of thermal expansion. They are used in …..
• Thermostats
• Heat engines
• Pressure cookers
• Pressure gauges
Answer: Thermostat
47. What is the resultant pressure when a force of 152N is applied on an area of 0.00095 m2?
• 1.6 x 105 Pa
• 1 52.095 Pa
• 1.44 Pa
• 6.25 x 10-5 Pa
Answer. 1.6 x 105 Pa
48. Which of the following heat engines runs in reverse?
• Gasoline engine of automobile
• Home air conditioner
• Jet airplane engine
• Stream engine of locomotive
Answer: Jet airplane engine
49. Which of the following would you open to separate a piston?
• Head bolt
• Connecting rod
• Valve plate
• Guzzle pin
Answer. Gajan Pin
50. If churning is not suitable for making ice cream, what could be the reason?
• Motor rpm is low
• Refrigerant quantity is low
• Dryer is clogged
• Compressor is short cycled
Answer. The rpm of the motor is low
For all candidates preparing for ITI RAC exams, this post contains very important information about RAC objective questions pdf in Hindi, iti refrigeration and air conditioning old question papers, refrigeration and air conditioning question paper pdf, iti RAC trade question paper. If you find this information useful, share it with your friends and if you want to know or ask something about it, then make sure to ask by commenting below.